Intermediates and dyestuffs of the anthraquinone series



Patented June 5, 1934 UNITED STATES INTERMEDIATES AND DYESTUFFS OF THEANTHRAQUINONE SERIES Paul Nawiasky, Ludwigshafen on the Rhine, BertholdStein, Mannheim, and Anton Vilsmeier, Ludwigshafenon-the-Rhine, Germany,

assignors to General Aniline Works, Inc., New 'York, N. Y., acorporation of Delaware No Drawing. Original application December 3,

1931, Serial No. 578,840. Divided and this application December 6,

1982, Serial No. 646,022.

In Germany December 11, 1930 7 Claims.

The present invention relates to intermediates and dyestuffs of theanthraquinone series and process of producing same.

We have found that valuable anthraquinone ,5 derivatives are obtained byheating with copper or cuprous chloride 2-amino-anthraquinonescontaining in the 1-position a halogen atom or a diazo group and inwhich both of the hydrogen atoms of the amino group are replaced by the10 carbonyl groups of a dicarboxylic acid, the said anthraquinonescorresponding to the general formula:

in which X2 and Z2 each stand for two hydrogen atoms or for one carbonatom, X2, Z2 and the two carbon atoms connected therewith being membersof the same nucleus of an aromatic compound which may be substituted, Ystands for halogen or the diazo 'group, and in which the anthraquinonenucleus may be substituted. The anthraquinone nucleus in the saidcompounds may be substituted by alkyl groups, for example methyl, ethyl,propyl, butyl and their isomeric groups, by hydroxy, alkoxy, aryloxy oracylamino groups, or by halogen,'viz. chlorine and bromine, in thebeta-position. These compounds may be obtained by heating l-halogen-2-aminoanthraquinones with succinic acid anhydride or with aromaticortho di'carboxylic acid anhydrides or its substitution products, suchas for example the anhydrides of phthalic acid, or 40 naphthaleneortho-dicarboxylic acids, preferably in the presence of halides, such asfor example ferric chloride, zinc chloride, phosphorus pentachloride andthe corresponding bromides. The said aromatic dicarboxylic acidanhydrides may be substituted by methyl or nitro groups or by chlorine.The corresponding diazo compounds may be prepared by the same method bystarting from 1'-nitro-Z-amino-anthraquinones reducing the nitro groupafter condensation with the 59 anhydride and diazotizing the aminogroup, or

by acting on the condensation products ofl-halogen-2-aminoanthraquinones and the aforesaid dicarboxylic acidanhydrides with a toluenesulphonic acid amide, splitting off thetoluenesulphonic acid by dissolution in concentrated sulphuric acid atabout room temperature and diazotizing the product in the said solution.

The condensation of the l-halogen-2-dicarboxylimidoanthraquinones bymeans of copper is preferably carried out in an organic solvent,especially in such solvents as have a high boiling point, for examplesubstituted benzenes, such as halogenated and nitrated benzenes andhomologues thereof, naphthalene and its alkyl, halogen and nitroderivatives, diphenyl and its derivatives, paraffin oils and the like.The corresponding diazo compounds are condensed by means of cuprouschloride in water or a dilute acid, for example acetic acidand sulphuricacid.

The resulting compounds which are 1.1-dianthraquinonyl derivatives, are,generally speaking, difficultly soluble in organic solvents and more orless colored. They are important initial materials for the preparationof dyestuffs into which they are converted by a process which comprisessaponification.

Saponification of the beforedescribed condensation products is effectedby causing them to react with basic or acid saponifying agents, but thesaponification can take place in different ways. Thus the ring formed bythe dicarboxylic acid radicle and the nitrogen atom can only be split upwith the formation of an acylamino compound containing in the acylradicle a carboxylic group, or the dicarboxylic acid can be split offcompletely with the formation ofthe free amine, or the completesaponification can take place simultaneously with condensation todyestuffs of the flavanthrone series. The exact conditions under whichthe one or other kind of saponification takes place cannot be given,since the specific saponification occurring depends not only on the kindof saponifying agent employed, whether acid or alkaline, but also on itsconcentration, the period of time for which the saponification iscarried on and the temperature. Products in which the ring formed by thedicarboxylic acid radicle and the nitrogen atom is split up with theformation of acylamino compounds are obtained when carrying outsaponification with alkaline agents not merely diluted with water, butalso with organic diluents, such as for example alcohols, and attemperatures which, generally speaking, should not exceed 80 C. The freeamines are preferentially obtained by saponification with substitutionproducts of ammonia, such as for example hydrazine hydrate andethylenediamine, in organic solvents, in particular such as are misciblewith water, for example pyridine, piperidine, quinoline, phenols,

cresols and the like, and at temperatures between about room temperatureand 50 C. saponification and simultaneous condensation occurs by meansof the aforesaid reagents when carrying on the saponification overextended periods of time and/or at higher temperatures. The use of acidsaponifying agents, for example sulphuric acid and hydrochloric acid,practically always leads to simultaneous saponification andcondensation. Here again the reaction can lead to different productsdepending on the concentration of the acid used, on the one hand todyestuifs of the flavanthrone series and on the other hand tocondensation products in which apparently one amino group is split offand replaced by a hydroxy group. This latter kind of simultaneoussaponification and condensation is eifected, in general, when sulphuricacid of more than 90 per cent strength is used, whereas by theemployment of more dilute sulphuric acid from about 20 to '90 per centstrength and at temperatures which are the higher the more the sulphuricacid is diluted and should be above about 90 C., preferably above 150 C.With 20 per cent sulphuric acid, dyestufis of the flavanthrone seriesare obtained. The difierences occurring in the saponification of thecondensation product of l-chlor- 2-phthalimidoanthraquinone by means orsulphuric acid of different concentration may be illustrated as follows:By the action of 96 per cent sulphuric acid on the said condensationproduct, a yellow product is obtained which dissolves in sulphuric acidgiving a blue red coloration. When treated with alkaline hydrosulphitesolution, this product becomes olive in color without passing intosolution. By heating the said initial material with from 85 to 90 percent sulphuric acid and then pouring the sulphuric acid solution intowater, a compound having the character of a yellow vat dyestuff isobtained.

Simultaneous saponification and condensation of the2.2dicarboxylimido-l.1-dianthraquinonyls to dyestuffs of theflavanthrone series also take place on saponification with aqueousdilute alkaline agents at temperatures which should be at least 90 C. inorder to complete the reaction in a reasonable time. The upper limit ofthe temperature which may be used, depends only on the stability of theinitial material and the products, and may, therefore, be chosen as highas 250 C. or even higher. The application of such temperaturesnecessitates working under superatmospheric pressure. Dilute solutionsof alkali which may be used, are for example caustic alkalisolutions offrom 1 to 10 per cent strength, or correspondingly diluted solutions ofammonia and derivatives thereof, such as hydrazine hydrate,ethylenediamine and the like, di-sodium and (ii-potassium phosphate,alkaline earth metal oxides and the like. From the foregoing it will beseen that by means of dilute alkaline, as well as acid, saponifyingagents quite generally, dyestuffs of the flavanthrone series areobtained and from these agents the alkaline agents give the bestresults.

The partially saponified products and those completely saponifiedproducts which have not undergone condensation, may be converted intodyestufis of the flavanthrone series under the aforedescribed conditionsleading from the dicarboxylimidodianthraquinonyls to the said dyestuffs.In addition thereto the free diamines may be converted into the saiddyestuffs by simply heating them, even to above their melting points, orin the presence of an organic solvent,

such as for example acetic anhydride, glacial acetic acid, naphthaleneand its substitution products and the like, if necessary under pressure,or-by dissolving them in concentrated sulphuric acid.

The following examples will further illustrate the nature of thisinvention but the invention is not restricted to these examples. Theparts are by weight.

Example I .20 parts of succinic acid anhydride are heated to about 210C. after the addition of 0.2 part of sublimed ferric chloride, whereupon26 parts of 1-chlor-2amino-anthraquinone are slowly added. The reactionmixture is heated at the said temperature until splitting off of wateris completed and initial material cannot any more be detected inappreciable amounts. The reaction mixture is then poured into 60 partsof hot nitrobenzene and allowed to cool. Nearly colorless crystals ofl-chlor-Zsuccinimidoanthraquinone separate out on cooling. They dissolvein concentrated sulphuric acid giving a yellow solution.

Example 2 1 part of ferric chloride is introduced into 250 parts ofphthalic acid anhydride kept at 220 C. and thereupon 100 parts of1.3-dibrom-2- aminoanthraquinone. The temperature is then raised toabout 235 and 240 C. and kept there at until the initial anthraquinonederivative can practically no more be detected. The excess of phthalicacid anhydride is then extracted by means of boiling water, or .sublimedoff. The l.3-dibrom2-phthalimidoanthraquinone thus obtained crystallizesfrom nitrobenzene in yellow crystals dissolving in concentratedsulphuric acid to give a yellow solution.

When replacing the 1.3-dibrom-2-aminoanthraquinone by the equivalentamount of l-chlor 3 methyl 2 aminioanthraquinone thel-chlor-3-methyl-2-phthalimidoanthraquinone is obtained.

Example 3 A mixture of 20 parts of l-chlor -aminoanthraquinone, 0A partof sublimed ferric chloride and 14 parts of phthalic acid anhydride and120 parts of dry nitrobenzene is heated to boiling until the splittingoff of water is completed. The reaction mixture is then allowed to cooland the separated pale yellow crystals are recovered in the usual way.The 1-chlor-2-phthalimidoanthraquinone thus obtained dissolves inconcentrated sulphuric acid giving a pale yellow solution.

When replacing the phthalic acid anhydride by 3.6-dichlorphthalic acidanhydride 1-chlor-2 p-dichlorphthalimidoanthraquinone is obtained.

Example 4 40 parts of 1chlor-2-aminoanthraquinone, 0.4 part of sublimedferric chloride and 40 parts of nathphalene-2.3-dicarboxylic acidanhydride are heated in 300 parts of dry nitrobenzene at about 210 C.until 1-chlor-2-aminoanthraquinone cannot any more be detached. Thereaction mixture is then allowed to cool, the product filtered off andwashed with ethyl alcohol. The 1 chlor 2 naphthalene-2.3'dicarboxylimidoanthraquinone thus obtained in the form of lightyellow crystals dissolves in concentrated sulphuric acid giving a yellowsolution.

Imixture is diluted with chlorbenzene.

Example 5 10 parts of 1-chlor-Z-phthalimidoanthraquinone are heated with5 parts of copper and 40 parts of naphthalene to boiling until nofurther increase in the amount of condensation product formed can bedetected. The resulting con densation product is then freed from solventand copper in the usual manner. The compound obtained is a yellowcolored crystalline powder which dissolves in cold sulphuric acid givinga pale yellow coloration. When warmed the solution becomes an intenseblue red. The product is free from chlorine. It dissolves with greatclifficulty in organic solvents of high boiling point 25;, and hasamelting point far above 300 C.

Example 6 parts of 1-chlor-2-phthalimido-3-methylanthraquinone aredissolved in 120 parts of tri- 30 chlorbenzene and heated to boilingwith 30 parts of copper powder until initial material can no longer bedetected. The whole is filtered by suction at 100 C. and the inorganicconstituents are removed from the residue in the usual manner. Yellowcrystal grains are obtained which crystallize from nitrobenzene in theform of beautiful greenish yellow flat prisms. They dissolve insulphuric acid giving a yellow coloration which changes to blue red whenthe solution is heated. The blue red solution has a sharp spectrum andis distinguished by the fact that its color rapidly changes in sunlight.Its melting point is above 300 C.

When employing in the abovedescribed reaction1-chlor-2-phthalimido-3-methoxyanthraquinone instead of the 3-methylderivative described, a condensation product is obtained which is verysimilar in its properties to the above described product.

Example 7 30 parts of l.3-dibrom-Z-phthalimidoanthraquinone togetherwith 10 parts of copper powder are heated to boiling for several hoursin 90 parts of trichlorbenzene. The insoluble inorganic I precipitate isfiltered off by suction while hot and the whole allowed to cool.Beautiful pale yellow short prisms separate out from the filtrate. Thesedissolve in sulphuric acid giving a yellow coloration. If this yellowsolution be heated to 100 C. the color changes to blue red. The meltingpoint of the compound is above 300 C.

Example 8 10 parts of l-chlor-Z-succinimidoanthraquin one are mixed with5 parts of copper powder and introduced into 20 parts of boilingnaphthalene. The mixture is then kept boiling while stirring untilunchanged 1-chlor-Z-succinimidoanthraquinone is practically no longerdetectable. The When the inorganic admixtures have been removed in theusual manner, the reaction product remains behind in the form of heavyyellow crystal grains. The resulting compound dissolves in concentratedjsulphuric acid giving a yellow coloration. When heated this solutionbecomes blue red in color. The product is free from chlorine and meltsabove 300 C.

Example 9 Example 10 37 parts of l-amino-2-phthalimidoanthraquinone-(obtainable by acting on l-chlor-phthalimidoanthraquinone withp-toluenesulphonic acid amide and saponifying the product by means ofsulphuric acid) are dissolved in 300 parts of concentrated sulphuricacid and diazotized by slowly introducing '7 parts of sodium nitrite,whereupon the sulphuric acid solution is poured into 2,000 parts ofice-cold water. The solution thus obtained is then run into a suspensionof 25 parts of cuprous chloride in 500 parts of water kept at between 95and 100 C. whereby nitrogen is evolved. The mixture is then boiled for ashort time, the precipitate filtered off and freed from inorganicsubstances by boiling with dilute nitric acid. The reaction productconsisting of grey yellow particles is then worked up in the usualmanner. It may be freed from small amounts of impurities byrecrystallization from nitrobenzene or trichlorobenzene. The product isidentical with that described in Example 5.

Example 11 25 parts of the product obtainable according to Example 5 arefinely divided and heated with 750 parts of 10 per cent ammonia at from150 to 180 C. until the splitting oil of dicarboxylic acid radicles ispractically completed. The resulting orange yellow product is filteredoff and worked up in the usual manner. It dyes cotton powerful yellowshades from a deep blue vat.

Example 12 Example 11.

Example 13 10 parts of the initial material employed in Example 11 areheated at from 150 to 170 C. with 400 parts of a 5 per cent solution ofdisodium phosphate until the splitting off of dicarboxylic acid radiclesis practically completed. The working up is effected as in Example 11.The dyestuif agrees with the product described in Example 11, as regardsall its properties.

Example 14 10 parts of the compound obtainable accord- The dyestuff isidentical with that obtained according to ing to Example 8 are heated to160 C. for several hours with 400 parts of a 5 per cent soda solution.In this way the greenish yellow particles are converted into fine brownred needles. These are isolated in the usual manner and dye cottonorange shades from apure blue vat.

Example 15 10 parts of the compound described in Example '7 in 100 partsof ortho-dichlorbenzene are stirred at 150 C. with 10 parts of hydrazinewhile leading air in until the reaction is completed. In order toisolate the final product, the whole may be stirred with an alkalinehydrosulphite solution in which the product dissolves with a deep bluecoloration. By leading in air, an orange colored paste is obtained whichyields a blue vat from Which cotton is dyed orange yellow shades.

Example 16 10 parts of the initial material employed in Example 11 areheated to from 150 to 170 C. with 50 parts of a 5 per cent solution ofsodium carbonate until the splitting ofi of the dicarboxylic acidradicle is practically completed. The mixture is then worked up asdescribed in Example 11. The dyestuff obtained corresponds with thedyestufi described in Example 11 as regards all its properties.

If the 5 per cent solution of sodium carbonate be replaced by a l percent solution of caustic soda the same reaction product is obtained.

Example 17 10 parts of the product obtained according to Example 8 areheated in a finely divided form With 300 parts of 5 per cent causticsoda at the boiling point until the conversion of the yellowishparticles of the initial material into fine yellow needles is completed.The mixture is worked up as described in Example 11. The dyestuffobtained corresponds with that described in Example 11 as regards allits properties.

Example 18 10 parts of the product obtained according to Example 9 arebrought into a finely divided form by dissolution in cold concentratedsulphuric acid and reprecipitation by means of water and are thenstirred at from 95 to 100 C. with 250 parts of a 7.5 per cent solutionof caustic soda until the initial material is completely converted intofine yellow needles. The reaction product, after being worked up asdescribed in Example 11, corresponds with the dyestuff described in thesaid example as regards all its properties.

Example 19 5 parts of the product obtainable according to Example 5 arebrought into a finely divided form and stirred with 100 parts ofpyridine. 3 parts of hydrazine hydrate are then added to the resultingsuspension at 20 C. After a short time dissolution takes place with aslight increase in temperature and the formation of a golden browncoloration, and at the same time colorless crystals of the phthalic acidcompound of hydrazine are precipitated. When initial material canpractically no longer be detected, the hydrazine salt is filtered off bysuction and 100 parts of water are added to the filtrate. In this mannera brilliant red intermediate product is deposited in the form ofbeautiful leaflets. This is converted into fiavanthrene by dissolving itin concentrated sulphuric acid.

Example 2.0

10 parts of the product obtainable according to Example 5 in a finelydivided form are introduced at room temperature into a mixture of 100parts of ethyl alcohol, 100 parts of water and 10 parts of caustic soda.The suspension is warmed to between 50 and 60 C. whereby a nearlycomplete dissolution to an orange yellow solution takes place. The smallamounts of undissolved substance are filtered off and the filtrate runinto hydrochloric acid whereby an intensively yellow colored precipitateseparates out. The precipitate is filtered off and washed with water.The compound thus obtained is soluble in cold dilute soda solution incontradistinction to the initial material. The yellow color of thissolution changes to orange red on addition of caustic soda. On heatingthe orange red solution obtained for example in a 4 per cent aqueouscaustic soda solution at about 95 or 100 C., the dyestufi described inExample 11 is obtained. The same dyestuff is also obtained by heatingthe intermediate product in dilute soda solution with dilute sulphuricacid.

Example 21 10 parts of the compound obtainable according to Example 5are heated to 120 C. in 100 parts of 85 per cent sulphuric acid. In thismanner the solution which is originally pure yellow becomes more reddishyellow. When no further alteration in the color can be observed, thesolution is allowed tocool somewhat and then water is allowed to drop inat about 90 C. until brownish yellow crystals commence to separate out.After cooling the mixture is filtered by suction and the residue freedfrom acid by washing with water. In this way a brown crystal powder isobtained which is soluble in sulphuric acid of 96 per cent strengthgiving a reddish yellow coloration. It dyes cotton powerful yellowshades from a deep blue vat.

Example 22 5 parts of the compound obtainable according to Example 5 areheated to 95 C. with 75 parts of 96 per cent sulphuric acid. The yellowsolution thus rapidly becomes intense blue red. When no further increasein the intensity of the coloration can be observed the mixture isallowed to cool and 25 parts of water are allowed to fiow in slowly at90 C. while stirring. In this way orange yellow needles separate out.These, after cooling completely, are filtered off by suction and washedfirst with '70 per cent sulphuric acid then with water and finally withmethanol. The color of the crystals is thus changed to greenish yellow.It may be obtained in the form of thin yellow leaflets-from pyridine inwhich it is soluble with difiiculty. These leaflets dissolveinconcentrated sulphuric acid giving a brilliant blue red coloration;the solution has a characteristic spectrum and rapidly changes insunlight.

The leaflets are soluble in a mixture of equal parts of piperidine andwater to give a currantbrown coloration; this indicates the presence ofacid groups.

If, instead of stirring water into the concentrated sulphuric acid, thesulphuric acid solution be allowed to flow into 2'75 parts of methanol,yellow leaflets which are as good as insoluble in methanol immediatelyseparate out. These are very similar in their properties to the reactionproduct separated by the addition of water 5 but they are not soluble ina mixture of equal parts of piperidine and water. It is probable thatthey constitute a methylated form.-

Errample 23 1 part of the compound obtainable according to Example 5 isheated ,to- 200 C. for several hours with 40 parts of concentratedhydrochloric acid. The yellow crystals of the initial material are thusconverted into brown crystals. These contain chlorine and dissolve incaustic soda solution giving an intense blue coloration. The bluesolution has the character of a dyestuif vat and dyes cotton yellowshades.

Example 24 3 parts of the compound obtainable according to Example 5 areheated at 200 C. with 100 parts of 20 per cent sulphuric-acid until theconversion of the yellow particles of the initial material into fineorange red crystals is completed. These are isolated in the usual mannerand correspond to a great extent with the compound obtainable accordingto Example 21 as regards their properties.

Example 25 10 parts of the compound obtainable according to Example '7are heated at from 90 C. with 150 parts of sulphuric acid containing 96per cent of H2804 until the color of the solution which is originallyyellow but which gradually changes to strawberry red undergoes nofurther change. The mixture is allowed to cool to 40 C. and then 450parts of methanol are stirred in. Yellow leaflets separate immediatelyand are isolated in the usual manner. They dissolve in concentratedsulphuric acid giving an intense strawberry red coloration; the solutionhas a characteristic spectrum which compared with the spectrum of thesulphuric acid solution of the compound obtainable according to Example22 is clearly displaced towards blue. The reaction product stillcontains bromine and is insoluble in a mixture of equal parts ofpiperidine and water.

The present application is a division of our copending application Ser.No. 578,840, filed December 3rd, 1931.

What we claim is:-

1. In the manufacture of dyestuffs of the anthraquinone series the step,which comprises causing a 1.1'-dianthraquinonyl corresponding to theformula:

in which X2 and Z2 each stand for two hydrogen atoms or for one carbonatom, X2, Z2 and the two carbon atoms connected therewith being membersof the same nucleus of a compound of the benzene or naphthalene series,in which derivato react with a saponifying agent.

3. In the manufacture of dyestuffs of the anthraquinone series the step,which comprises heating a 1.l'-dianthraquinonyl corresponding to theformula:

with a dilute alkaline saponifying agent at a temperature above about 90C.

4. In the manufacture of dyestuffs of the anthraquinone series the step,which comprises heating a 1.1-dianthraquinonyl corresponding to theformula:

with a sulphuric acid of between 20 and 90 per cent strength at atemperature above about 90 C.

5. In the manufacture of dyestuffs of the anthraquinone series the step,which comprises causinga l'.l-'di anthraquinonyl corresponding to theformula:

7; In the manufacture of dyestuffs of the anthraquinone series the step,which comprises heating a 1.1'-dianthraquinonyl corresponding to theformula:

to react with a saponifying agent. I

6. In the manufacture of dyestuffs of the anthraquinone series the step,which comprises heating a 1.1'-dianthraquinonyl corresponding to with aSulphuric ac of from 20 to 90 P cent the formula: strength at atemperature above about 90 C.

PAUL NAWIASKY. BERTI-IOLD STEIN. ANTON VILSMEIER.

with a dilute alkaline saponifying agent at a temperature above about 90C.

